#[derive(Debug)] pub enum Node { // Structure Nodes Document { children: Vec }, Heading { level: u8, children: Vec }, Paragraph { children: Vec }, List { ordered: bool, children: Vec }, ListItem { children: Vec }, CodeBlock { children: Vec }, BlockQuote { children: Vec }, ImageNode { src: String, alt: String }, // Inline Nodes Text { content: String }, Bold { content: String }, Italic { content: String }, BoldItalic { content: String }, Code { content: String }, Link { href: String, content: String }, } impl Node { /// Recursively convert a node into a HTML string. This is used to generate the DOM output /// tree. This should only be called on the root node of the tree. This function will recursively /// call itself to create the entire tree. /// /// Currently, this function does not create indentation, that would be a nice touch though. pub fn to_html(&self) -> String { match self { // Structure nodes Node::Document { children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!( "\n\n\n\n\nDocument\n\n\n{}\n", inner ) } Node::Heading { level, children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!("{}\n", inner, level = level) } Node::Paragraph { children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!("

{}

\n", inner) } Node::List { ordered, children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); let tag = if *ordered { "ol" } else { "ul" }; format!("<{tag}>{}\n", inner, tag = tag) } Node::ListItem { children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!("
  • {}
    • \n", inner) } Node::CodeBlock { children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!("{}\n", inner) } Node::BlockQuote { children } => { let inner = children.iter().map(|x| x.to_html()).collect::(); format!("
    {}
    \n", inner) } Node::ImageNode { src, alt } => format!("\"{}\"\n", src, alt), // Inline nodes Node::Text { content } => format!("{}", content), Node::Bold { content } => format!("{}", content), Node::Italic { content } => format!("{}", content), Node::BoldItalic { content } => format!("{}", content), Node::Code { content } => format!("{}", content), Node::Link { href, content } => format!("{}", href, content), } } /// Determines if a node is empty. For structure nodes (those with `children`) this will be /// true when there are no elements in the list. For inline nodes (those without `children`) /// this will be true when the string content of all fields are blank. pub fn is_empty(&self) -> bool { match self { // Structure nodes Node::Document { children } | Node::Heading { level: _, children } | Node::Paragraph { children } | Node::List { ordered: _, children, } | Node::ListItem { children } | Node::CodeBlock { children } | Node::BlockQuote { children } => children.is_empty(), // Inline nodes Node::Text { content } | Node::Bold { content } | Node::Italic { content } | Node::BoldItalic { content } | Node::Code { content } => content.is_empty(), // Special rules Node::Link { href, content } => content.is_empty() && href.is_empty(), Node::ImageNode { src, alt } => src.is_empty() && alt.is_empty(), } } /// Returns Some children if they exist, otherwise None will be returned. For nodes that do not /// have children, None will be returned. pub fn children(&self) -> Option<&[Node]> { match self { // Structure Nodes Node::Document { children } | Node::Heading { level: _, children } | Node::Paragraph { children } | Node::List { ordered: _, children, } | Node::ListItem { children } | Node::CodeBlock { children } | Node::BlockQuote { children } => Some(&children), // Inline Nodes Node::Text { content: _ } | Node::Bold { content: _ } | Node::Italic { content: _ } | Node::BoldItalic { content: _ } | Node::Code { content: _ } => None, // Special Nodes Node::Link { href: _, content: _ } => None, Node::ImageNode { src: _, alt: _ } => None, } } /// Add a child to the back of the list of children. If the node is a type which does not allow /// children to be added, this function will panic. pub fn add_child(&mut self, child: Node) { match self { // Structure Nodes Node::Document { children } | Node::Heading { level: _, children } | Node::Paragraph { children } | Node::List { ordered: _, children, } | Node::ListItem { children } | Node::CodeBlock { children } | Node::BlockQuote { children } => children.push(child), // Inline Nodes Node::Text { content: _ } | Node::Bold { content: _ } | Node::Italic { content: _ } | Node::BoldItalic { content: _ } | Node::Code { content: _ } => panic!("Can't add child to this node type."), // Special Nodes Node::Link { href: _, content: _ } => panic!("Can't add child to this node type."), Node::ImageNode { src: _, alt: _ } => panic!("Can't add child to this node type."), }; } } #[cfg(test)] mod node_tests { use super::Node; }